Stabilization of carotenoid material



. 3 081 171 fsTABHLEZATION BF CAE tDTENOID MATERIAL Robert A. Beiners, Hinsdale, and Robert E. Morgan, Oak Lawn, 1th., assignors to Corn Froducts Company, New

view of the face that at lower concentrations (for example, 2 percent) soybean lecithin exerts almost no stabilatent I Patented Mar. 12, 1963 ECQ izing effect on these pigments. The efi'ectiveness at vari ous concentrations is shown in Table I.

The method for determining the oxidative stability of these xanthophyll oil-soybean lecithin blends is as fol- Ymrkg NY a comomtim f Delaware lows: Samples in the amount of 3 ml. each of the blend No Di-awing Filed Sept 1, 1959, Sen 837,339 to be tested were put into SO-ml. beakers and these beak- 4 Cl i ((31, 99 2) ers placed in a forced air-circulation oven held at 50 C.

Usually 8 samples of each blend were started at one time.

This invention relates to stabilization of oleaginous At frequent intervals .a beaker was removed from the solutions of carotenoids. 10 oven, the entire sample dissolved in hexane and the total The object of this invention is the preparation of a carotenoid pigment content determined. The results stable oleaginous carotenoid solution suitable for use in from a series of samples taken at different times were feed formulations. Carotenoids are one of the principal plotted to determine the time required for a 50 percent types of plant pigments. They are characterized by their pigment loss. intense color, their solubility in oil and by a highly un- Blends of xanthophyll oil and soybean lecithin are saturated structure. The parent compound of this series easily prepared; the two liquids need merely be mixed is beta-carotene, a precursor to vitamin A. Its structure together. This procedure, although effective, is slow due is shown below: to the high viscosity of the lecithin, therefore, it is desir- CH3 CH CH3 CH3 CH3 CH3 \C/ The carotenoids with which we are principally conable to heat the mixture mildly to assure better mixing. cerned here are those found in corn. The chief pigment Common laboratory practice is exemplified in the example is zeaxanthin, 3,3-dihydroxy-beta-carotene; cryptoxangiven below: thin, the 3 hydroxy-beta-carotene, is also present in ap- Fifty grams of soybean lecithin, sold under the despreciable quantities as is beta-carotene itself. Alphaignation Gliddol grade N by the Glidden Company, was carotene and its corresponding mono and d-ihydroxy deadded to 50 grams of xanthophyll oil and the mixture rivatives are present in small quantities. heated to 60 C. under a nitrogen blanket with mild agi- All these compounds are characterized by a long chain tation. The mixture was removed from the steam bath of conjugated double bonds. It is the presence of this and stirred an additional 10 minutes to insure good mixing. unsaturation that accounts for the intense color of the Samples (3-rnl.) of this blend were pipetted into clean oarotenoids. it also accounts for the susceptability of 50-1111, bearers and the beakers placed in a forced circuthese compounds to oxidation. While the course of oxig lation air oven held at 50 C. At the desired intervals a dation has not been completely elucidated, it is apparent beaker was withdrawn from the oven and its contents that oxidation does lead to the formation of less highly analyzed. The results are given below: colored or colorless compounds.

In describing this invention, it is convenient to use 0 xanthophyll oil as an example. It is to be understood, Days at O 0 14 2L 36 however, that this invention may 'be applied to other v oleaginou-s solutions of carotenoids having a different Totalplgmenumyflb') L295 L100 960 647 carotenoid composition. I

Xanthophyll oil is obtained as a try-product of the exstablhty of 1115 mple Y es 36 days, the time retraction of zein from corn gluten. It is essentially a l for P F W 9 of i U mixture of the fatty compounds and the oil soluble pig- 50 s 1691mm Fommercial Product Wmch, 1S ments from corn gluten. The carotenoids of x-anthophyll 'avallable m 3 Quamltles- It is mafia y treatfnf oil are principally those compounds mentioned previously, crude Soybean 011 With er and separat ng the precipitheir positional isomers and their degradation products. ta'te from the bulk of the Q Thls p l j 't 1S y- The total carotenoid pigment content of this oil will q under Vacuum T10 Yi Y- 1601mm, a dark usually run from 0 mo 4 percent with the hydroxy 55 material of grease-l ke consistency at roomtemperature. camtenes making up 7() 9() percmt f the an It may be fluidized in :a vanetyof ways to yleld a viscous Xanthophyll oil has found a ready market as a comtq 9 t F and fiuld gmfiifis are q y 3516c poncnt in chicken feeds. The hydroxycarotenes in this 1W6 as amloxldanis for P 3 n have ham Shown to cause h f t of the bird to The composition oi soybean lecithin is quite complex come yellow, a feature which improves the sale-ability of f F Its mdlvldual compounds ,have not been the chicken considerably identified. The commercial product contains about 35-fi0 One of the problems in the manufacture and sale of Percent triglycerides 69 p 303mm xanthophyll oil is the lack of stability of its pigments solublesf latter 3TB Y P p i Such as 11 On exposure to air, especially at elevated temperatures, p ohne, phosphaudyl ethanolanune, phosphatidylthe pigment 3011mm of xanthophyn i drops idl 65 serine, plasmalogens and the mositol phospnatides. Other We have discovered that soybean lecithin is an unusually wmpounds which are F T Stemls, p y effective antioxidant for olcaginous solutions of caroglycosidfis, and q p This gross PQ P 1S tenoids, provided it is employed at concentrations of from not partic y dlfiefent di of Com lficlthtll, Y about 25 to about 75 percent. This is very surprising, in 70 the latter is ineiiiective in stabilizing xanthophyll 011.

The stabilizing efEect of soybean lecithin is not due simply to dilution of the pigments. Such diluents as crude '2 corn oil or crude soybean oil either did not appreciably affect the stability of the pigments in xanthrophyll oil or improved them by a factor of onyl 3 to 4.

The stabilizing effect of soybean lecithin on the carotenoid pigments of xanthophyll oil is retained even in the presence of diluent oils. This is shown in the data of Table II. Again major quantities of soybean lecithin are required to stabilize the blends.

The advantages of this invention are that for the first time we have a practical, inexpensive way to stabilize xanthophyll oil pigments. The edibility of soybean lecithin has been well established, thus there is no fear of harmful effects to the animals. Stabilization of xanthophyll oil will permit long distance shipment or prolonged storage without 'fear of decomposition of the carotenoid pigments.

Theuniquefeature of this invention is the effectiveness of large quantities of soybean lecithin in preventing carotenoid oxidation, whereas amounts ordinarily recommended for antioxidants are relatively ineffective. Evans (Ind. Eng. Chem. 27, 329 (1935)), 'for example, uses a maximum of 0.1 percent in vegetable oils. It is'characteristic of most antioxidants that dosages above a certain low level are not effective in increasing the stability of the substrate. Thus, alpha-tocop-herol, a naturally occurring antioxidant, at concentrations above 0.06 percent did not further extend the stability of lard (Oil and Soap 21, l8893 (1944)). The same is true of the synthetic antioxidants (The Hormel Institute Publication No. 20, page 10 (1947)). In our case we have found the amounts conventionally used to be ineffective; until about 25 percent soybean lecithin by weight is added 'tothe blend, the improvement in stability is oflittle practical value. The upper practical limit is about 75 percent.

'Soybean lecithin is unique in that it is the only antioxidant cheap enough to be economically useful at so. high a concentration. And its physical characteristics-are such that resulting product is a viscous oil which can be easily handled.

TABLE I Efiect of Various Amounts of Soybean Lecithin on the Stability of Xanthophyll Oil Amount Amount Pigment Lecithin Xantho- Stability Protection (Percent) phyll Oil at 50 0. 'Factor (Percent) (days) None 100 2 1.0

TABLE II Dilution of Lecithin-Xanthaphyll Oil Blends Composition of Blend (Percent) Stability Protection at 50 0. Factor Xantho- Soybean (day phyll Lecithin Diluent Oil '50 '50 0 22 11.0 50 25 25'Crnde soybean oil 16 8.0 50 1O 40 Crude soybean oil 7 3. 5 0 50 Crude soybean oil 4 2. 0 5D 0 50 Yellow grease 2 1. 0 50 25 25 Yellow grease 27 13. 5

We claim:

1. A composition of matter stable to oxidative deterioration and liquid at normal temperatures consisting essentially of from about to about 25 percent, by weight, of an oleaginous earotenoid material and about 25 to about 7-5 percent, by weight, of soybean lecithin.

2. A process for stabilizing an oleaginous carotenoid solution which consists essentially of adding about 25 to about 75 percent, by weight of the final composition of soybean lecithin to fromabout 75 to about 25 percent, by weight of the final composition, of an oleaginous carotenoid material, saidfinal composition being liquid at normal temperatures.

3. A composition of matter stable to oxidative deterioration and liquid at normal temperatures consisting essentially of from about 75 to about 25 percent, by weight, of xanthophyll oil and about 25 -to about 75 percent, by weight, of soybean lecithindissolved therein.

4. A process for stabilizing xanthophyll oil which consists essentially of adding about 25 to about 75 percent, by weight of the-final composition, of. soybean lecithin to ,from about 75 toabout 25 percent, by weight of the final Musher Apr. 23, 1940 'Scharf Mar. 24, 1953 Kruse Feb. 9, 1960 

1. A COMPOSITION OF MATTER STABLE TO OXIDATIVE DETERIORATION AND LIQUID AT NORMAL TEMPERATURES CONSISTING ESSENTIALLY OF FROM ABOUT 75 TO ABOUT 25 PERCENT, BY WEIGHT, OF AN OLEAGINOUS CAROTENOID MATERIAL AND ABOUT 25 TO ABOUT 75 PERCENT, BY WEIGHT, OF SOYBEAN LECITHIN. 